net: add copy_safe_from_sockptr() helper

copy_from_sockptr() helper is unsafe, unless callers
did the prior check against user provided optlen.

Too many callers get this wrong, lets add a helper to
fix them and avoid future copy/paste bugs.

Instead of :

   if (optlen < sizeof(opt)) {
       err = -EINVAL;
       break;
   }
   if (copy_from_sockptr(&opt, optval, sizeof(opt)) {
       err = -EFAULT;
       break;
   }

Use :

   err = copy_safe_from_sockptr(&opt, sizeof(opt),
                                optval, optlen);
   if (err)
       break;

Signed-off-by: Eric Dumazet <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

0 files changed, 0 insertions, 0 deletions